The report, released Monday by the Pew Forum on Religious and Public Life, appears to be the most extensive research ever done on D.C.-based lobbyists and advocates on faith matters. It documents the widening range of domestic and foreign issues religious groups push and fight and shows the entrance in recent years of religious minority groups, such as Muslims, Sikhs and secular organizations, into the field.

The survey identifies the work of 212 faith-oriented groups, which spend about $390 million per year. That is up from less than 40 such groups in 1970.

The biggest spenders, the survey says, include the American Israel Public Affairs Committee, the U.S. Conference of Catholic Bishops, and established social conservative groups focusing on abortion, same-sex marriage and home-schooling. The report’s authors said that the science of identifying “religious” advocates was imprecise but that they picked groups that said they were driven by faith convictions.

Some longtime Hill advocates highlighted the report’s finding that the vast majority of religious advocates stick to softer education-type outreach and don’t get into explicit politics, such as donating money to candidates. Others said the report showed how tiny the field is, compared with the tens of thousands of mostly corporate lobbyists that have ballooned in number in Washington.

“No one is going on a golfing vacation in Scotland with us,” said John Carr, a policy advocate for the Catholic bishops, who first came to the Hill in the 1970s. “Washington is awash with money, and it’s harder to break through.”

The United States Conference of Catholic Bishops, the Vatican’s U.S. arm, is the second-largest spender, investing $26.7 million in advocacy, according to the study.

But others saw the growth of the field as corrupting.

“Religious lobbyists used to be like subsistence farmers, and now it’s like agribusiness,” said the Rev. Barry Lynn, executive director of Americans United for Separation of Church and State, the 15th-biggest spender, with $6.3 million spent on advocacy in 2008, according to the Pew study.

The study noted that 80 percent of the groups are registered as tax-exempt nonprofit organizations, meaning they are restricted in how much direct lobbying they can do. But some watchdog groups that focus on money in politics have said that federal law exempts some religious organizations from having to disclose communications related to lobbying.

The work of religious advocates mirrors the issues that come and go in public life. Early groups focused on trying to ban alcohol and funding for Native American schools. Different issues rose and fell, as did organizations.

The Moral Majority, once one of the nation’s largest advocacy groups with millions of members, closed its Washington operations in the late 1980s as religious conservatives became more confident that their values were being heard. The study noted that the Unitarian Universalist Association of Congregations, also eliminated its D.C. office “due to declining revenues.”

Compared with their numbers in the U.S. population, Muslims and Jews make up a bigger chunk of advocates. There are 17 Muslim advocacy groups and 25 Jewish advocacy groups, while the faith groups represent less than 1 percent and 1.7 percent of the American public, respectively, according to Pew. About 8 percent of groups identify as mainline Protestant, compared with being 18 percent of the population.

The study doesn’t attempt to measure influence, but veterans in the field say the religious advocacy groups wield a particular kind of clout.

“I think there is a grudging respect for consistency, even with people who disagree with us,” said Carr, whose group has been active in several recent policy debates, such as protecting entitlements for the poor during budget-cutting this year and adding tougher antiabortion language to House legislation on health care in 2009. “But the reality is, our priorities are not Washington’s. This is a mission, not a job.”

Maggie Gallagher, co-founder of the National Organization for Marriage, a new group aimed at fighting same-sex marriage, said that religious conservatives have been too meek about getting directly involved in the political part of lobbying and that might change.

“There’s a sense that there is a sacredness in religion that doesn’t mix easily with the nitty-gritty of politics, that politics is a dirty business,” she said. “The upside is that this is an area with a lot of room for growth.”